CVE-2026-98638

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Validate the SVE vector length in pkvm vcpu init sve()

pkvm vcpu init sve() clamps only the upper bound of the host-provided sve max vl, so an invalid vector length reaches sve state size from vl() and the WARN ON() there, which is fatal at EL2. The existing !sve state size test rejects such a length, but only after the macro has run.

Check sve vl valid() before deriving the state size. A valid length cannot yield a zero size, so the !sve state size test goes with it.